1. Field of the Invention
The present invention relates to an adjustment display for ski bindings which cooperate with one end of a boot and which are adapted to respond to forces exerted in a horizontal plane, i.e., parallel to the plane of the ski.
2. Description of the Prior Art
Bindings which comprise at least one lateral retention element for a boot are known. It is common for this lateral retention element to be adapted to move with respect to the ski so as to allow to the release of the boot when a lateral force of the boot exceeds a pre-set value or threshold, thereby preventing bodily harm to the skier. It is, therefore, very important that the adjustment of the release threshold of the binding be correct. In addition, it is also important that the positioning of the retention element with respect to the sole of the boot, which is a determining factor with respect to the reliability of the release threshold, be correct. It is also important that the skier be aware of whether the retention element is properly or improperly adjusted so as to be able to make the necessary corrections.
A typical ski boot binding jaw comprises a plurality of boot retention elements which assure the retention of the boot in a horizontal plane. At least two of these elements are normally adjustable with respect to each other to adapt the binding to the length, width, and configuration of the boot.
Normally, the adjustment of the position of the boot relative to the retention elements is made visually by perceiving the play which exists between retention elements and the sole of the boot. Alternatively, sheets, made of plastic for example, are interposed between the retention elements and the sole of the boot and are removed after the adjustment. These sheets, therefore, function as thickness gauges to measure the play between the boot and the retention elements. In this method, verification of the proper adjustment is also performed visually, which is a particularly unreliable manner of verification.
Another type of verification involves noting a "hard point" in the rotation of an adjustment screw when a retention element, for example, a lateral wing, makes contact with the boot. This "sensitive" method is likewise of little reliability. Furthermore, improper adjustments can always occur after this initial adjustment, particularly because of various phenomena, such as, the presence of snow wedged between the sole of the boot and the retention elements.
French Pat. No. 2,309,257 attempts to solve this verification problem by providing a vertical bias detector which senses the forces exerted by the binding on the sole of the boot during rest, for bindings in which these vertical forces would normally be absent. A mechanical indicator, normally flush with a surface, moves to the edge of a reference surface in the event the binding experiences abnormal forces. However, determining the position of this mechanical indicator again involves a purely visual and at best a subjective verification of the adjustment of the retention elements. An improvement is provided by substituting an electro-mechanical indicator for the mechanical indicator, wherein, in the case of an excessive vertical constraint, a mechanical element closes an electronic interruptor controlling the energization of a bulb.
The apparatus described in the French patent, however, has a number of inadequacies resulting from its construction. In addition, it can only detect an abnormal vertical force such as a pinching of the sole, and, cannot sense any horizontal force resulting from, for example, improper positioning of the sole of the boot with respect to the pertinent retention elements in the horizontal plane.
A much more complex type of detector is proposed in French Application No. 2,430,778. In this type of detector, one or more electrical contacts are activated by pressure from the sole of the boot when the sole is abnormally pinched in the vertical direction by the front jaw or the rear stop, because of, for example, snow under the sole. Again, in this case, it is not possible to note a defective positioning of the retention elements with respect to the sole of the boot in a horizontal plane.